JPS6376971A - Solenoid valve for flow rate regulating - Google Patents

Abstract

PURPOSE:To securely carry out control over the plural stages of the flow rate of fluid by providing plural springs for increasing a valve closing load by stages during the move of a valve stem which is integrally formed with a plunger which is moved by electromagnetic force, from a totally closed condition to a fully opened condition. CONSTITUTION:A stator 3 is provided on the center part of an exciting coil 2 housed inside a case 1, and a plunger 4 which is movable back and force along an axial direction is provided on the coaxial line of the stator 3. A valve part 6 is integrally provided on the end of a valve stem 5, which is fixed to the axis of the plunger 4 and the valve stem 5 is energized in a valve closing direction by a valve closing spring 11 provided in between the stator 3 and the plunger 4. Also, a valve opening spring 13 is provided in between a movable spring bearing 12 which is fitted over the outer peripheral part of the valve stem 5 on the valve seat 8 side from the plunger 4 and the outer peripheral part of the valve seat 8, energizing the valve stem 5 in the valve opening direction. And, the valve closing load of the valve closing spring 11 is set larger than the valve opening load of the valve opening spring 13, to maintain a valve closing condition when the exciting coil 2 is not electrified.

Description

[Detailed description of the invention] B2 Purpose of the invention E1. Industrial applications The present invention relates to a solenoid valve for adjusting flow rate.

E2. BACKGROUND ART Conventionally, as shown in FIG. 10, a solenoid valve that adjusts the flow rate of fluid in two stages has been used, as shown in FIG.
), a valve shaft (33) provided with a valve part (32) is fixed to the valve part (32), and a first spring (34) is compressed and interposed in the valve part (32) to bias the valve part (32) in the valve-opening direction at all times; Furthermore, a second spring (35) is provided at the tip of the valve stem (33) to apply a load in the valve closing direction to the valve stem (33) during the movement of the valve stem (33) in the valve closing direction. and the second spring (3
5), but in the closed state, the valve is in an uncompressed state and the pressing load is set to zero, for example, in the Japanese Patent Publication No. 58-1.
It is disclosed in Japanese Patent No. 5661.

E30 Problems to be Solved by the Present Invention In the conventional device, the second spring (35) that acts after opening the valve is
Since the initial operating load is set to zero, after the valve is opened, the valve-closing load of the second spring acts from zero in the transition area where the valve-opening load of the second spring (35) acts. Therefore, the valve-closing load characteristics of the spring at the time when the second spring acts after the valve is opened and on the way to full opening form a gentle curve that corresponds to the movement of the valve stem. Therefore, the movement characteristic of the valve shaft that moves in the opening direction against the valve closing load also becomes a gentle curve as shown in FIG. 11, which increases in proportion to the value of the current flowing through the exciting coil. This means that the flow rate characteristics of the solenoid valve with respect to the current value change in an analog manner as shown in FIG. 11(A).

Therefore, if the current value varies in the width (Y) in FIG. 11 in the intermediate region, there is a problem in that the flow rate of the fluid passing through the electromagnetic valve also varies in the width (X).

Therefore, the present invention controls the fluid flow rate in multiple stages by stopping the movement of the valve stem in the valve opening direction as the current value increases, and in particular, in the stepwise stop position. A solenoid valve for flow adjustment that prevents the valve stem from changing even if the current value fluctuates within a predetermined range, and that does not cause variations in the fluid flow rate even if the current value varies when the valve stem is stopped. The purpose is to make suggestions.

9. Structure of the Invention 10. Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a plunger that is attracted and moved in the valve opening direction by an electromagnetic force generated by energizing an excitation coil, and A valve stem that is fixed and moves together with the plunger, a valve seat that is opened and closed by a valve section provided on the valve stem, and a valve seat that is attached to the valve stem while moving from a fully closed state to a fully open state. It consists of a plurality of springs for increasing the valve closing load stepwise multiple times and a movable spring receiver that engages the springs and the valve shaft, and furthermore, the plurality of springs are subjected to a pressing load in their initial state. It is characterized in that it is installed in a compressed state so that it has .

When the valve stem shifts to the next stage's open state due to an increase in the electromagnetic force acting on the low 20, the valve stem receives the valve closing load of the spring for the next stage.
At this time, since the spring for the next stage is installed in a compressed state so that it has a pressing load in its initial state, the valve is closed until the electromagnetic force increases until the pressing load of this spring overcomes the valve closing load. The shaft does not move in the valve opening direction. Therefore, from the time when the spring load for the next stage is applied to the time when the spring load for the next stage is overcome, the valve stem does not move even if the current value changes during that time, and there is no variation in the fluid flow rate.

Row 3. Embodiment Next, an embodiment of the present invention shown in FIGS. 1 to 3 will be described.

(1) is a case in which an excitation coil (2) is installed. (3) is a stator provided at the center of the excitation coil (2). (4) is a plunger provided so as to be movable back and forth along the axis of the excitation coil (2), and its rear end face faces the stator (3).

A valve stem (5) is fixed to the axis of the plunger (4),
A valve part (6) is integrally formed at the tip part, and the rear end face is
A stopper surface (7) is formed that comes into contact with the stator (3) to restrict the backward movement of the valve stem (5). (8) is a valve seat provided facing the valve portion (6);
) is spaced apart from the valve seat (8), so that a flow rate of fluid corresponding to the separated flow area flows from the fluid inlet (9) to the fluid outlet 0ω. (11) is a valve-closing spring interposed in a compressed state between the stator (3) and the plunger (4), which constantly biases the valve shaft (5) in the valve-closing direction via the plunger (4). There is. (12) is a movable spring receiver, which is connected to the valve part (8) from the plunger (4).
The outer peripheral portion of the valve stem (5) on the side is housed in the case (1) so as to be slidable in the axial direction of the valve stem (5).

(13) is a valve opening spring interposed in a compressed state between the outer circumference of the valve seat (8) and the movable spring receiver (12), and constantly biases the movable spring receiver (12) in the valve opening direction. ing.
The rear surface of the movable spring receiver (12) is attached to the plunger (4).
is in separable contact with the front surface of the (14) is a spring stopper against which the rear surface of the movable spring receiver (12) comes into contact, and is fixed to the case (1) side.

The valve-closing load of the valve-closing spring (11) is set larger than the valve-opening load of the valve-opening spring (13), and the excitation coil (
2), the valve closing spring (11
The valve closing load of ) overcomes the valve opening load of the valve opening spring (13) to maintain the valve closed state as shown in FIG.
The gap (old) between the movable spring receiver (12) and the spring stopper (14) in this valve closed state, and the gap (Dz) between the stopper surface (7) and the stator (3) on the valve shaft (5),
Opposing gap (D3) between plunger (5) and stator (3)
) is set to D, <D, <D.
In the figure, (15) is a cord for energizing the excitation coil (2).

Next, the operation of this embodiment will be explained.

When the excitation coil (2) is not energized, the valve-closing load of the valve-closing spring (11) overcomes the valve-opening load of the valve-opening spring (13), and the valve is in the closed state as shown in Figure 1. . The relationship between the current and the movement stroke of the valve stem (5) in this state is at point (A) in Figure 6, and the flow rate of the fluid is at point (A) in Figure 6.
It is zero at the position (A) in the figure. Next, excitation coil (2)
is energized, the current value is increased, and the current value becomes higher than the valve closing load of the valve closing spring (11).
The plunger (4) is not attracted to the stator (3) until it reaches point (B) in Fig. 6, where an electromagnetic force equivalent to the remaining valve-closing load after subtracting the valve-opening load in step 3) acts. Part (6
) is in a closed state, and the fluid flow rate is zero up to point (B) in FIG. Next, the current value further increases from the point (B), and the total load of the attraction force of the plunger (4) in the valve opening direction due to the electromagnetic force and the valve opening load of the valve opening spring (13) increases. When the valve closing load of the valve closing spring (11) is overcome,
The valve shaft (5) moves together with the plunger (4) in the valve opening direction, and the stroke of the valve portion (6), that is, the valve opening area increases, reaching point (C) in FIG. 6.

In this state, as shown in Fig. 2, the movable spring receiver (12) is in contact with the spring stopper (14), and the flow rate of the fluid is increased from point (B) to point (C) in Fig. 7. Ru. Note that the rise from point (B) to point (C) in Fig. 6 is almost vertical because the gap (Dl) is small, but due to sliding friction of the valve stem, etc. Tilt as shown.

Next, when the current value is further increased from the point (C), the valve opening force due to the electromagnetic force increases, but after the point (B), the valve opening load due to the valve opening spring (13) is unchanged. The valve opening spring (
The help in the closing direction due to 13) disappears. Therefore, in order to further move the plunger (4) in the valve opening direction, a valve opening load equivalent to that of the extinguished valve opening spring (13) is required. Therefore, until the current value increases from the point (C) to the point (D) where an electromagnetic force equivalent to the valve opening load of the valve opening spring (13) is applied, the plunger (4)
is not attracted in the valve opening direction, and the stroke of the valve shaft (5) in the valve opening direction does not increase beyond point (C). Therefore, even if the current value increases to point (D), the fluid flow rate does not increase until it reaches point (D) in FIG. Next, the current value is shown in Figure 6 (D
) When the valve opening load increases due to electromagnetic force, the opening/closing load overcomes the valve closing load of the valve closing spring (11), the plunger (4) is attracted and moved in the valve opening direction, and the valve shaft The stroke in the valve opening direction (5) increases to point (E) in FIG.

Therefore, the flow rate of the fluid is increased to point (E) in FIG. The state of this point (E) is the state shown in FIG.
The rising state from point (D) to point (E) in FIG. 6 is the same as the rising state from point (B) to point (C). In this state at point (E), the stopper surface (7) at the rear end of the valve stem (5) contacts the stator (3), so even if the current value increases to (F) above, the valve portion ( 6) does not move further and the fluid flow rate remains unchanged. The relationship between the stroke of the valve shaft (5) in the valve-opening direction and the valve-closing force exerted by the spring during such a valve-closing operation is shown by the solid line (A) in FIG.

Next, a state in which the current value is decreased from the above-mentioned valve open state will be explained. Until the current value decreases from point (F) to point (E) in FIG. 6, the stroke of the valve portion (6) does not change as described above, and the flow rate of the fluid does not change as shown in FIG. 7. When the current value decreases from point (E), the stroke of the valve stem (5) does not immediately decrease as the current value decreases, and the stroke of the valve stem (5) does not decrease immediately after the current value decreases to point (G) as shown by the broken line. The stroke decreases to point (H) as shown by the broken line. The reason why the stroke change point of the valve stem (5) shifts compared to when the current value increases is because the electromagnetic force acting on the plunger (4) is proportional to the distance between the plunger (4) and the stator (3). This is because the valve-closing force of the valve-closing spring (11) is proportional to the distance between the plunger (4) and the stator (3), although it is proportional to the square of the square. Next, while the current value decreases from point (H) to point (C), the stroke of the valve stem (5) does not change due to the same force relationship as when the current value increases, and the flow rate of the fluid also does not change. . Next, when the current value decreases to point (1), the stroke of the valve stem (5) is as shown by the broken line (J)
decreases to a point. The reason why the stroke change point of the valve stem (5) deviates by 1 point compared to point (C) when increasing is due to (
This is the same reason why point (G) is shifted from point E).

When the current value decreases to this point (J), the stroke of the valve stem (5) becomes zero and the valve is closed, and the current value becomes (A
The closed state continues until the flow rate decreases to a point ), and the fluid flow rate becomes zero as shown in FIG.

FIG. 4 shows a second embodiment of the present invention, in which a second valve-closing spring (13) is used instead of the valve-opening spring (13) in the previous embodiment.
16) and the movable spring receiver (12) is provided at the rear of the valve shaft (5).

That is, a movable spring receiver (17) is slidably provided in the stator (3) facing the stopper surface (7) of the valve shaft (5), and the rear surface of the movable spring receiver (17) and the case (1) are slidably provided in the stator (3).
), and a second valve closing spring (16) is compressed and interposed between the adjusting screw (18) and the adjustment screw (18) screwed into the valve.

The rest of the structure is the same as that of the previous embodiment.

In this second embodiment, when the current value of the exciting coil (2) increases from the valve closed state shown in FIG. (4) is not suctioned, and the valve portion (6) is in an open state. Next, the current value increases further and the valve closing spring (1
When the valve closing load of 1) is overcome, the plunger (4) moves by suction and the valve portion (6) opens.

When the current value further increases and the force comes into contact with the movable spring receiver (17) on the stopper surface (force) of the valve stem (5), the second valve closing spring (1
The valve shaft (5) stops due to the valve closing load of 6). Even if the current value increases, the valve stem (
5) stops and the current value increases until it generates an electromagnetic force that overcomes the valve closing load, the movable spring receiver (17) resists the valve closing load of the second valve closing spring (16). The stroke of the valve stem (5) in the valve opening direction increases. The stroke characteristics of the valve stem (5) with respect to such current values are similar to those shown in FIG. 6, and the flow rate characteristics are also similar to those shown in FIG. 7.

However, the slope of the valve-closing force by the spring is different from that of the embodiment described above, as shown by the broken line (b) in FIG.

FIG. 5 shows a third embodiment of the present invention, and as shown in FIG. 4, a second movable spring receiver (19) is slidable on the outer periphery of the movable spring receiver (17) of the second embodiment. In addition, a third valve-closing spring (20) is compressed and interposed between the rear surface of the second movable spring receiver (19) and the case (1).

The other structure is the same as the second embodiment.

In this third embodiment, the fluid flow rate changes in three stages as the current value increases, and at the time of the change, the valve stem (5)
The stroke of will not change.

FIG. 9 shows a fourth embodiment of the present invention, which is a modification of the valve portion in the second embodiment. In other words, the valve seat (
21) is formed into a cylindrical shape, and a fluid inlet (
22), and a cylindrical valve part (23) is attached to the valve seat (22).
1), and the inlet port (
It forms an opening/closing opening (24) that engages with the valve part (23).
) The flow rate of the fluid is controlled by the amount of polymerization of the opening/closing port (24) relative to the inlet (22) by sliding. (25) is a pressure transmission passage. The rest of the structure is almost the same as the embodiment shown in FIG. This embodiment has the advantage that the pressure caused by the fluid flow hardly affects the valve closing load of the spring.

C1 Effects of the Invention As described above, according to the present invention, the flow rate of the fluid can of course be changed in multiple stages, and in particular, the movement characteristics of the valve stem with respect to the current value, that is, the flow rate characteristics of the fluid can be changed as shown in FIG. 11(B). Like,
Between the flow rate change point in the first stage and the flow rate change point in the second stage,
Even if the current value changes, the flow rate does not change in a digital manner, so between the flow rate change point in the previous stage and the flow rate change point in the latter stage, as shown in Fig. 11 (B), the excitation coil Even if there is a variation in (Y) width in the current value, the movement of the valve stem, that is, the variation width (Z) in the fluid flow rate will be
This is significantly smaller than the conventional variation width (X) shown in FIG. 1 (A). Therefore, the solenoid valve has the advantage of being able to adjust the flow rate in multiple stages with high precision even if there are variations in the current value.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the first embodiment of the present invention, FIGS. 2 and 3 are side sectional views showing its operating state, and FIGS. 4, 5, and 9 are side sectional views showing the first embodiment of the present invention. Each side sectional view showing the other three embodiments, Fig. 6 is a characteristic diagram showing the relationship between current value and valve stem stroke, Fig. 7 is a flow rate characteristic diagram, and Fig. 8 is a spring versus valve stem stroke. Figure 10 is a sectional view showing a conventional solenoid valve, and Figure 11 is a comparison diagram of the flow rate characteristics with respect to current value between the conventional type and the present invention.
A) shows the conventional one, and (B) shows the one of the present invention. (2)...Excitation coil (3)...Stator (4)...Plunger (5)...Valve shaft (6)...Valve part (8)...Valve seat

Claims (1)

[Claims] A plunger that is attracted and moved in the valve opening direction by electromagnetic force caused by energizing an excitation coil, a valve shaft that is fixed to the plunger and moves together with the plunger, and a valve seat that is opened and closed by a valve section provided on the valve shaft. A plurality of springs and the springs engage with the valve stem to gradually increase a valve-closing load on the valve stem multiple times while the valve stem moves from a fully closed state to a fully open state. 1. A solenoid valve for adjusting a flow rate, characterized in that the plurality of springs are installed in a compressed state so as to have a pressing load in an initial state.